Process of refining lubricating oils



Patented Aug. 4, 1931 was STATES PATENT orrica WIRI D. RIAL, OE WATSON, CALIFORNIA PROCESS OF REFINE-1G LUBBICATING OILS No Drawing.

hydrocarbons of the naphthenic series in ad dition to certain undesirable percentages of sulphur bearing hydrocarbons, unstable unsaturated hydrocarbons and oxygenated products. I

These sulphur bearing hydrocarbons, unstable unsaturated hydrocarbons and oXy genated hydrocarbons must be separated as 9 con'ipletely as possible from the more stable hydrocarbons'in order to produce a lubricating oil of'high quality.

By Well-known methods, the treating of lubricating oil stocks derived from an asphalt or mixed base crude petroleum oil requires the use of relatively large amounts of sulphuric acid, caustic soda and a final decolorizing treatment with a decolorizing agent, such as Florida fullers earth. acid-treated montmorillonite, magnesium silicate and the like. such treatments the lubricating oil stock produced, although purified to a com- 'paratively' high degree, may contain small. percentages of impuritiessuch as oxygenated hydrocarbons in sufiicient amounts to emulsify' with water when employed in steam turbines or for other lubricating. purposes where the oil comes into contact with steam or Water. c

I am aware that certain methods are now known whereby lubricating, oil stocks from c an asphalt or mixed base crude petroleum oil may be specially treated to eliminate these impurities, but such processes involve either the use of expensive re-agents such as alcohol and the like, or other such methods which result in low yields. I

Now,.I have discovered a process whereby these difficulties may be overcome and a high grade lubricating oil produced which will Application filed February 13, 1929. Serial No. 339,738.

not emulsify when commingled with water,

steam, or a water solution of caustic soda and one which can be employed for any kind of lubrication Without further special treatments.

An ob ect of the invention is to refine lubrieating oil stocks derived from an asphalt or mixed base petroleum oil so as to economically produce a treated oil which will not emulsifyandcommingle with water or a water solution of caustic soda;

Another object of the invention is to produce a lubricating oil suitable for lubricating steam turbines or other machinery.

' Another object of the invention is to produce a lubricatingoil of high purity and substantially free from emulsifying constituents.

Another object of the invention is to pro duce a high grade lubricating oil substantially free from resins, gums, organic acids,

phenols, organic sulpho-acids, unstable unsaturated hydrocarbons and corrosive sulphunbearing hydrocarbons.

Another object of the invention is to accomplish the above with a minimum loss in the final yield of the lubricating oil stock.

Other advantages of the invention will appear in the'practical use of the same and from the following description.

For illustration, lubricating oil distillate derived by fractional distillation, at a rereduced pressure, from an asphalt base rosiduum or fuel oil from which the lower boiling oils have been separated, is continuously discharged into re-run stills and therein continuously subjected to a second distillation at a reduced pressure, care being taken that no air comes into contact with any of the products of distillation.

The vaporized products from the re-run stills are condense-d, allowing no contact of air therewith, and immediately subjected to 'a pressure treatment with a water solution of potassium hydroxide in the presence of steam which is employed to commingle the lubricating oil stock and the water solution of potassium' hydroxide. This operation is carried out in accordance with the process as given in the pending application of John C. Black and Wirt D. Rial, Serial No. 187,110,

filed April 27, 1927, process of refining lubricating oils, which comprises treating lubricatingoil stocks or distillates with a water solution of potassium hydroxide, agitating with steam under a pressure greater than at mospheric, and at a temperature of approxi- I veiition to prevent any air contact with the I lubricating'oil stock or distillate prior to this 7 "treated with acid at the rate of approximately I mately-280 to 300 degrees ii. to dissolve and separate emulsifying constituents before any substantial oxidation can take place.

. Therefore, it is an essential step of this intreatment with potassium hydroxide The separated treated lubricating oil stock I after the treatment under steam pressure with the water solution of potassiumv hydroxide is 3% toas'high as l pound or a little higher, of 66 degree Bauin sulphuric. acid per gallon of oil,-by methods'welldrnown in the art; f The acid-treated oil separated from the ac d reaction products, is then subjected to a neutralization. operation consisting in commingling the oil with calcium hydroxide and an adsorbentv clayla-t'ateinperature. of approximately 300 degreesF., after which the treated oil is separated frointhe calciumhy- Y dioxide and adsorbent Clay CODt&1I11ng the adsorbed constituents, this operation being conducted in accordance-with the pending application of John C. Black, l/Vii't D. ltialand Raymond T. Howes, Serial No. 104,836,:fi1ed April 26, 1926, process of purifying petroleum oils, granted October 10, 1928, Patent No. 1,709,203 of April 16, 1929..

2. That step in theprocess of refining lubricating oil stocks, comprising, separating by Vacuum distillation a lubricating oil stock from an asphalt or mixed base crude petroleum oil, immediately with the exclusion of air condensing and re-distilling the lubricating oil stock as produced, condensing the ire-distilled lubricating oil stock with the exclusion of air and immediately treating the same in liquid phase with a water solution of potassi- 'um hydroxide in the presence of steam to separate the oxidizable constituentstherefrom. In testimony whereof I affix my signature. WIRT D. RIAL.

The lubricating oil stock, atter'the aforeyVVh ile the process herein described is well adapted for carrying out the object of the-in vention, it is to be understood that :VflllOHS changes and modifications may be made without departing from the spirit of the invention and'the invention includes all; such changes and modifications as come with-in the scope of the appended claims. i "What Iclaim is: v I n 1. Thatstep intheprocessi of refining iii- A bricating oil stock's,comprisi ng, separating by vacuum distillation a lubricating 011 stock vfrom an asphalt or mixed base,crudepetroleum oil, continuously and immediately with the exclusion of air condensing and re-dis tilling the lubricating oil stock asproduced,

continuously condensing the re-distilledlubricating oil stock with the exclusion of air and immediately treating the'fsame in liquid 7 phase with a water-solution ofpotassiumhydroxide in the presence of steam to separate the oxidizable constituents theref rom. 

